Note 17 - Income Taxes - Major Tax Jurisdictions in Which the Company and Affiliates Operate and the Earliest Tax Year Subject to Examination (Details)	12 Months Ended
	Aug. 31, 2018
Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member] | Minimum [Member]
Open tax years	2015
Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member] | Maximum [Member]
Open tax years	2018
State and Local Jurisdiction [Member] | Minimum [Member]
Open tax years	2015
State and Local Jurisdiction [Member] | Maximum [Member]
Open tax years	2018
Foreign Tax Authority [Member] | Her Majesty's Revenue and Customs (HMRC) [Member] | Minimum [Member]
Open tax years	2015
Foreign Tax Authority [Member] | Her Majesty's Revenue and Customs (HMRC) [Member] | Maximum [Member]
Open tax years	2018
Foreign Tax Authority [Member] | Ministry of the Economy, Finance and Industry, France [Member] | Minimum [Member]
Open tax years	2016
Foreign Tax Authority [Member] | Ministry of the Economy, Finance and Industry, France [Member] | Maximum [Member]
Open tax years	2018
Foreign Tax Authority [Member] | Federal Ministry of Finance, Germany [Member] | Minimum [Member]
Open tax years	2017
Foreign Tax Authority [Member] | Federal Ministry of Finance, Germany [Member] | Maximum [Member]
Open tax years	2018